Coating structure and method

Abstract

A coating structure including an outer coating comprising aluminum; and an interlayer disposed between a substrate and the outer coating is provided. The interlayer may include a rare earth metal, a transition metal, or a noble metal. The interlayer may have one or more property of being less responsive to halogen etching relative to the outer coating; having a coefficient of thermal expansion that is greater than the coefficient of thermal expansion of the substrate and less than the coefficient of thermal expansion of the outer coating or vice versa; having a color different from the color of the outer coating; having a electrical conductivity different from the electrical conductivity of the outer coating. A method of making is article is provided. The method may include securing an interlayer to a substrate surface, and securing an outer coating to a surface of the interlayer opposite the substrate.

1. A coating structure, comprising:
 an outer coating comprising aluminum; and 
 an interlayer disposed between a substrate and the outer coating, and the interlayer comprising one or more of a rare earth metal, a transition metal, or a noble metal; wherein the substrate comprises one or more of a metal nitride, a metal carbide, a metal boride, or a metal oxide, wherein the metal nitride comprises carbon doped boron nitride. 
 
     
     
       2. A coating structure, comprising:
 an outer coating comprising aluminum; and 
 an interlayer disposed between a substrate and the outer coating, and the interlayer comprising one or more of a rare earth metal, a transition metal, or a noble metal; wherein the substrate comprises one or more of a metal nitride, a metal carbide, a metal boride, or a metal oxide, wherein the metal nitride is pyrolitic boron nitride. 
 
     
     
       3. The coating structure as defined in  claim 1 , wherein the metal portion of the metal nitride, the metal carbide, the metal boride, or the metal oxide comprises one or more of tantalum, titanium, tungsten, zirconium, hafnium, lanthanum, vanadium, niobium, magnesium, chromium, molybdenum, or beryllium. 
     
     
       4. The coating structure as defined in  claim 1 , wherein the outer coating comprises one or more of aluminum nitride, aluminum oxide, or aluminum oxynitride. 
     
     
       5. The coating structure as defined in  claim 1 , wherein the outer coating has an average thickness in a range of from about 10 Angstroms to about 10 micrometers. 
     
     
       6. The coating structure as defined in  claim 1 , wherein the rare earth metal comprises cerium or gadolinium. 
     
     
       7. The coating structure as defined in  claim 6 , wherein the interlayer comprises an oxide of the rare earth metal. 
     
     
       8. The coating structure as defined in  claim 1 , wherein the transition metal comprises yttrium or hafnium. 
     
     
       9. The coating structure as defined in  claim 1 , wherein the interlayer comprises an oxide of the transition metal. 
     
     
       10. The coating structure as defined in  claim 9 , wherein the interlayer consists essentially of hafnium oxide. 
     
     
       11. The coating structure as defined in  claim 1 , wherein the noble metal comprises one or more of platinum, rhodium, rhenium, or palladium. 
     
     
       12. The coating structure as defined in  claim 1 , wherein the interlayer is microcrack free. 
     
     
       13. A coating structure, comprising:
 an outer coating comprising aluminum; and 
 an interlayer disposed between a substrate and the outer coating, and the interlayer comprising one or more of a rare earth metal, a transition metal, or a noble metal; wherein the substrate comprises one or more of a metal nitride, a metal carbide, a metal boride, or a metal oxide, wherein the interlayer comprises a silicate glass. 
 
     
     
       14. The coating structure as defined in  claim 13 , wherein the silicate glass comprises one or more of calcium, silicon, or boron. 
     
     
       15. The coating structure as defined in  claim 13 , wherein the rare earth metal is present in the silicate glass in an amount in a range of from about 10 weight percent to about 25 weight percent. 
     
     
       16. The coating structure as defined in  claim 13 , wherein the rare earth metal is present in the silicate glass in an amount in a range of from about 25 weight percent to about 60 weight percent. 
     
     
       17. The coating structure as defined in  claim 1 , wherein the interlayer has an average thickness that is greater than about 50 angstroms. 
     
     
       18. The coating structure as defined in  claim 1 , wherein the interlayer has an average thickness that is less than about 10 micrometers. 
     
     
       19. The coating structure as defined in  claim 1 , wherein the interlayer has an average thickness in a range of from about 50 Angstroms to about 500 nanometers.